Question

A study was conducted to determine whether an expectant mother’s cigarette smoking has any effect on the bone mineral content of her otherwise healthy child. A sample of 90 newborns whose mothers smoked during pregnancy has mean bone mineral content 0.097 g/cm and standard deviation 0.027 g/cm; a sample of 160 infants whose mothers did not smoke has mean 0.090 g/cm and standard deviation 0.025 g/cm. Assume that the underlying population variances are equal. Conduct the test at the 0.05 level of significance. What do you conclude? Show all work.

Answer 1

:- Average bone mineral content in mother who smoke

:-  Average bone mineral content in mother who did not smoke

To Test :-

H0 :-  

H1 :-  

Test Statistic :-

t = 2.0643

Test Criteria :-
Reject null hypothesis if


Result :- Reject Null Hypothesis

Decision based on P value
P - value = P ( t > 2.0643 ) = 0.04
Reject null hypothesis if P value < level of significance
P - value = 0.04 < 0.05 ,hence we reject null hypothesis
Conclusion :- Reject null hypothesis

There is sufficient evidence to support the claim that there has an effect of smoking on the bone mineral content.

Answer 2